Cutter-head



. (No Model.) 7

H. ERNSBERGER.

CUTTER HEAD.

No. 509,301. Patented Nov. 21, 1893.

772. K Wad/Ma,

UNIT D STATES PATENT OFFI E.

HARMEN 'ERNSBERGER, or NORTH CREEK, onto.

*. CUTTER-HEAD.

SPECIFICATION forming part of Letters Patent No. 509,301, dated November21, 1893. Application filed January 7, 1893. Serial No. 457.599. (Nomodel.) i

To all whom it may concern:

Be it. known that I, HARMEN ERNSBERGER, a cltizen of the United Statesof America, residing at North Creek, in the county of'Putnam and Stateof Ohio, have invented certain new and useful Improvements inCutter-Heads, of which the following is a specification, reference beinghad therein-to the accompanying drawings.

My invention relates to an improved cutterhead for planing-machines, andpossesses the following characteristics: The construction of the head issuch that I am enabled to secure the cutters therein without formingslots or bolt-holes in it; to place more cutters in a head of a givensize than has heretofore been practicable; to so secure the cutters inthe head that the strain on the cutter for the time being in contactwith the board to be planed is transmitted throughout the entire head,

thereby avoiding all danger of the latter breaking at any of itssockets; to secure the cutters inthe head in such a manner that theywill be supported at their cutting-edges on both sides, whereby allpossibility of the cutters springing is avoided, and also in such amanner that the cutters will make a shaving or draw out, incontradistinction to what is known as the scraping cut; and,furthermore, by the peculiar construction of the head andcutter-fastenings I am enabled to use cutters until they have been wornaway to less than one-third their original length.

In the drawings, Figure 1 is a perspective view of a cutter-head of myimproved form. Fig. 2 is an end view of the same. Fig. his a detail Viewof the fastening device, showing the parts separated.

Referring to the drawings, A is a cutterhead, having gudgeons l andcircular cuttersockets 2, in which latter are secured cutterknives B, ofa curvature corresponding to that of the sockets. The knives are securedin place in the sockets by fastenings 0, each of which consists of clamp-blocks '0, held apart by a bolt 4:, threaded at 5 and provided with anot 6, as will be fully understoodfrom Fig. 3. Each clamp-block has acentral'bolthole 7, into which the ends 8 of the bolt 4 project, abolt-head 9 being formed on .the bolt a short distance from one end.When the knife is put in place, the nut 6 is screwed up on the bolt 4,the. clamp-blocks are placed on the ends of the bolt, and the wholedevice slipped into the end of the knife socket. One clampblock is setto bear against the knife, an the other block to bear against the innersi e of the knife-socket, after which the nut 6 is screwed so as totighten up the clamp-blocks and hold the knife firmly against the head.

It is apparent that as the cutting-edge'of one -knife strikes thelumberthe strain will be borne in the first place by the portion a of the headbetween the knife-sockets; and, in all the forms of heads with which Iam acquainted, this portion was of'necessity made heavy enough to carryall the strain whereas by my construction the fastening device of thenext following knife'is made to act as a brace to sustain the portion aby transmitting the strain to the, next following portion a, which inturn is braced by the fastening device following it, and so onthroughout the seriesuntil at last a portion .of the strain is actuallytransmitted to the fastening device of the knife then in contact withthe lumber, thereby helping to hold the knife solidly and preventing allvibration. It Will thus be seen that I am enabled to make the portion aof a minimum thickness, which enables me to place more knives around theperiphery of the head than if the portions a were compelled to be of athickness suitable tobear all the strain unaided, as in the usual formsof heads.

Moreover, by this construction, being on abled to place the knivescloser on the periphery of the head, a greater number of cuts is madeper revolution of head than-in the old forms,whereby I am enabled eitherto feed the lu mber through the machine ata fasterrate for the samenumber of revolutions of the head, or to run the head at a slower'speedfor the same rate of feed of the material. Again, the

portions a being made. smaller than in the old form of head, acutter-head of my construction is much lighter for the same number ofknives, and in consequence I can revolve the head much faster withoutthe centrifugal force bursting the head than where the por- Lions a aremade heavy, thus permitting the lumber to be fed faster than when theold forms of heads are used.

As the only part of the knife which need project beyond the head is thecutting-edge,

it is plain that I may hold the knife as close to its extreme edge as Idesire. This advantage not only prevents vibration of the knife, buttakes all undue strain off the fastenings.

It will be seen that as the knives wear at the edge or are ground awayin sharpening, they may be pushed out so as always to project the-same,until they are almost entirely used up, and only enough remains topermit the clam p-blocks to hold them, when they may be removed and newknives inserted.

In a cutter-head using the form of fastening-device herein described,the bolte is arranged diametrically of the socket, and in order to keepthe fastening device from being thrown out by centrifugal force when thehead is revolving I make the circular sockets soas to contain more thanone hundred and eighty degrees of arc, whereby the centrifugal forcemerely tends to tighten the fastening device and holds the knifetighter.

As in my construction the knife is not slotted, it is much stronger,easier constructed, and, as before stated, may be almost entirely usedup before replacing with a new knife.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is

1. The combination, with a cutterhead having a series of knife-socketsand intervening solid portions, of a series of knives and a series of'strain-transmitting securing devices, each of which latter serves tohold a knife in its socket, the securing device abutting against thefront surface of its respect: ive knife and against the rear surface ofthe solid portion ofthe head forward of that knife.

2. The combination, with a cutter-head series of strain-transmittingsecuring-devices arranged diametrically of the knife-sockets, eachdevice abutting against the front surface of a knife and against therear surface of the solid portion forward of that knife.

4. The combination, with a cutter-head having a series of knife-socketsand intervening solid portions and a series of knives in said sockets,of a series of strain-transmitting securing devices for holding theknives in their respective sockets, each of said devices comprising abolt provided at one end with a block, which bears against the frontsurface of one of said knives, and at the other end with ascrew-threaded nut, which bears against the rear surface of the S0116.portion of the head forward of that knife.

In testimony whereofI affiX my signature in presence of two witnesses.

HARMEN ERNSBERGER.

Witnesses:

WM. HUNTER MYERs, M. O. MASSIE.

